3. Answer all parts (a) to (t) of this question. Consider a function 2 2 7r(:n,y) = 10 a:2 y2+a$y+be'\" +9, where a: E R, y E R and (a, b) are parameters. (d) [10 marks] Find the condition about (a, 5) under which the second-order condition for (a: = 0; y = 0) to a be local maximum